AU706111B2 - A dividing panel for a bin - Google Patents

Description

WO"97/47537 PCT/AU97/00324 1

TITLE

A DIVIDING PANEL FOR A BIN FIELD OF THE INVENTION This invention relates to a dividing panel for a bin and particularly relates to a dividing panel to convert a standard mobile garbage bin into independent compartments.

BACKGROUND ART Bin dividers are known and typically comprise a plastic panel which is inserted into a bin to divide the bin into at least two, but sometimes more, separate compartments. The divided bin can be used for low level sorting for the purpose of recycling.

The bin dividing panel must be sufficiently rigid to minimise deformation of the panel, especially if one compartment is loaded and the other compartment is empty. However, the dividing panel must also take up minimum space in the bin. The dividing panel must also be of a design to prevent or minimise waste being trapped by the panel as the bin is emptied.

One of our existing earlier dividing panels was formed from a single wall of plastic, and the wall was formed into concave and convex shapes. This provided a degree of strength to the dividing panel and reduced deformation.

Another known type of dividing panel is one which is corrugated in the longitudinal direction to reduce bowing or deformation of the panel. However, tests have shown that a purely corrugated panel is inadequate and does not overcome bowing of the dividing panel. If the panel bows too much, the panel can become torn away from the bin, or can become loosened, which can cause the panel to become dislodged when the bin is emptied (emptying of these bins usually occurs by a mechanical arm inverting the bin and vigorously shaking it into a refuse truck).

Another disadvantage with excessive bowing of the dividing panel is that this reduces the width of the WO97/47537 PCT/AU97/00324 2 bin at the bow point, which can cause rubbish to be trapped in the bin below the reduced width. It is found that for a typical rubbish or recycling bin of about 240 litres, a bowing of 40 millimetres, or less, is required.

OBJECT OF THE INVENTION The present invention is directed to a dividing panel which has reduced bowing when compared with a straight plane panel.

It is an object of the invention to provide a dividing panel which may overcome the abovementioned disadvantages or provide the public with a useful or commercial choice.

In one form, the invention resides in a dividing panel insertible into a bin to divide the bin into independent compartments, the panel having corrugations extending from adjacent an upper edge of the panel to adjacent a lower edge of the panel, and at least one hollow enclosed channel extending from adjacent an upper edge of the panel to adjacent a lower edge of the panel.

It is found that the combination of corrugations together with at least one hollow enclosed channel, provides surprising and unexpected improvements to the ability of the dividing panel to resist distortion, and also allows the panel to still remain relatively thin wall thereby minimising the space in the bin taken up by the panel.

The dividing panel typically extends from adjacent a bottom of the bin to adjacent the top of the bin. The panel may extend along or across the bin and this orientation is usually dictated by the type of refuse truck. Of course, any number of dividing panels may be inserted into the bin to divide the bin into two, three, four, or more, independent compartments.

The panel is preferably continuous and is conveniently formed from injection-moulded plastic of which a polyene such as polypropylene is an example. The panel is conveniently formed as a single wall structure WO'97/47537 PCT/AU97/00324 3 to minimise the thickness of the panel.

The panel is corrugated along its length such that when the panel is inserted into the bin, the corrugations extend longitudinally up and down the bin.

The corrugations may extend substantially across the panel width and they also extend substantially along the panel length.

Typically, the bin panel is corrugated in such a manner to provide three corrugations extending along the bin. The depth of each corrugation (by which is meant the spacing between an upper and lower part of the corrugations) can vary. A depth of between 10 to millimetres may be suitable, with a preferred depth being between 20 to 40 millimetres.

The thickness of the panel itself can also vary and typically is between 3 to 15 millimetres. The thickness will depend upon the type of plastic used and the fillers used in the plastic.

The at least one hollow enclosed channel preferably extends along the panel from adjacent a bottom edge of the panel to adjacent a top edge of the panel.

The at least one channel is preferably enclosed along its length, and may be closed ended, or have an open top and/or bottom end. It is also possible for the dividing panel to contain a number of shorter length channels which can be linearly aligned with each other and which may be spaced from each other and which may extend along the length of the dividing panel.

Preferably, a number of channels are provided across the dividing panel, and it is preferred that each channel extends from adjacent an upper part to adjacent a lower part of the panel.

If the thickness of the panel is sufficient, the channels may extend along and in the panel such that the channels are not readily visible from each side of the dividing panel. However, if the dividing panel is of a thin walled design, the channels may extend along one or both faces of the panel to form visible longitudinal WO97/47537 PCT/AU97/00324 4 ribs. It is preferred that between two to four channels extend along the dividing panel, the channels being in a spaced parallel relationship relative to each other.

It is further preferred that the channels extend around a mid portion across the dividing panel as this part of the panel is subject to the most deformation.

It is further preferred that the channels are formed integrally with the dividing panel, and the channels may be formed by injecting gas, such as nitrogen or other gas during formation of the panel to provide an enclosed gas channel.

The gas channel wall thickness may vary to suit, but it is found that a thickness of between 4 to 6 millimetres is suitable. The height, or depth of the gas channel can also vary and we find a height of between to 20 millimetres to be suitable.

The dividing panel may have a peripheral thickened edge, and this edge may be solid or substantially hollow.

BRIEF DESCRIPTION OF THE DRAWINGS Embodiments of the invention will be described with reference to the accompanying drawings in which Figure 1 shows a plan view of a dividing panel according to an embodiment of the invention; Figure 2 shows a panel according to a second embodiment; Figure 3 shows a panel according to a third embodiment; Figure 4 shows a panel according to a fourth embodiment; Figure 5 shows a panel according to a fifth embodiment; Figure 6 shows an edge portion of a panel according to an embodiment of the invention.

BEST MODE Referring initially to Figure i, there is shown WO 97/47537 PCT/AU97/00324 in plan view, a dividing panel 10 for a mobile plastic refuse bin, the bin typically being known as a "wheelie bin". These bins have a volume of about 240 litres.

Dividing panel 10 can insert into the bin to divide the bin into two independent compartments. Panel 10 may be attached either permanently or semi-permanently to the bin and this can be achieved by clips, and the like, which are already known in the art.

Panel 10 in the embodiment is formed from talcfilled polypropylene and the panel is formed by injection moulding. Panel 10 has a wall thickness of between 5 to millimetres, but this can, of course, vary depending on the required strength of the panel.

The prevent bowing or deflection of the panel when under load, four hollow enclosed channels 11 14 are integrally formed with panel 10. Each channel is filled with gas and is formed by injecting a suitable gas (for instance, nitrogen) into the mould as the panel is being formed. Channels 11 14 extend along the entire length of the panel. Each channel is 8 millimetres across, 10 millimetres in depth, and has a wall thickness of 2.5 millimetres. This is, however, a preferred form of the panel and is not considered to be limiting.

The panel itself is corrugated as illustrated in Figure 1, and channels 11 14 are spaced apart around the central zone of the channel as it is found that the maximum deflection occurs in this area. In the embodiment, channels 11 and 14 extend along one face of panel 10, while channels 12 and 13 extend along the other face. It can be seen that the channels function to provide the benefits of a double wall in the area of maximum load on the panel. By providing the channels in this manner, it is not necessary to make the entire panel of a double wall construction which is expensive and decreases the useable volume in the bin.

Figures 2 5 illustrate alternative ways of forming the channels. In Figure 2, the channels are formed entirely within the thickness of the wall of the W097/47537 PCT/AU97/00324 6 panel, while Figures 3, 4 and 5 show variations thereto.

Figure 6 illustrates a thickened edge 15 of the panel to provide strength.

The following examples and tables illustrate the relationship between the various components of the dividing channel.

Example 1: Number of Gas Channels 2 Gas Channel Wall Thickness LO Gas Channel Depth 16mm Corrugation Depth Flexural Modulus 870 MPa Maximum Displacement DX 46.4mm Approximate Volume 2760cm 3 The maximum deflection, occurs at the centre of the bin divider approximately one third of the way up from the bottom.

Example 2: Number of Gas Channels 3 Gas Channel Wall Thickness Gas Channel Depth 16mm Corrugation Depth Flexural Modulus 870 MPa Maximum Displacement DX 41.8mm Approximate Volume 2910cm 3 The addition of a third gas channel down the centre of the bin divider reduces the maximum deflection under load compared to Example 1.

WO 97/47537 PCT/AU97/00324 Example 3: Number of Gas Channels 4 Gas Channel Wall Thickness Gas Channel Depth 16mm Corrugation Depth Flexural Modulus 870 MPa Maximum Displacement DX 33.1mm Approximate Volume 3490cm 3 Further increasing the number of gas channels to four, and increasing the gas channel wall thickness to reducing the degree of gas blowing), brings the maximum deflection down comfortably below the desired 40mm deflection limit. This is, however, at a cost in the increase of the part volume.

Example 4: Number of Gas Channels 4 Gas Channel Wall Thickness Gas Channel Depth Corrugation Depth Flexural Modulus 870 MPa Maximum Displacement DX 35.9mm Approximate Volume 2700cm 3 Increasing the depth of the corrugations from to 35mm whilst reducing the gas channels to a depth of 10mm and channel wall thickness of 2.5mm (improving the gas blowing performance of the part during moulding), results in a maximum deflection in the same range as Example 3 above. The volume of the bin divider is, W0'97/47537 PCT/AU97/00324 8 however, significantly less than that found in Example 3.

Example Number of Gas Channels 4 Gas Channel Wall Thickness Gas Channel Depth Corrugation Depth Flexural Modulus 630 MPa Maximum Displacement DX 49.6mm Approximate Volume 2700cm 3 Changing the material used in Example 4 above from 40% talc content to 20% talc content results in a maximum deflection which exceeds the 40mm desired limit.

This indicates that in order to achieve the desired deflection limit with lower talc content material, further structural design improvement is necessary.

Example 6: Number of Gas Channels 4 Gas Channel Wall Thickness Gas Channel Depth Corrugation Depth 38mm Flexural Modulus 870 MPa Maximum Displacement DX 28.3mm Approximate Volume 2700cm 3 Further increasing the depth of corrugations from 35mm to 38mm based on a 40% talc content results in a maximum deflection well below the 40mm desired limit.

This result suggests that lower talc contents may achieve the 40mm limit using this bin divider design.

WO97/47537 PCT/AU97/00324 Example 7: Number of Gas Channels 4 Gas Channel Wall Thickness Gas Channel Depth Corrugation Depth 38mm Flexural Modulus 750 MPa Maximum Displacement DX 32.9mm Approximate Volume 2700cm 3 Changing the material used in Example 6 above from 40% talc content to 30% talc content results in a maximum deflection which is still below the desired limit of Example 8: Number of Gas Channels 4 Gas Channel Wall Thickness Gas Channel Depth Corrugation Depth 38mm Flexural Modulus 630 MPa Maximum Displacement DX 39.1mm Approximate Volume 2700cm 3 Further reducing the talc content to results in a maximum deflection is only just below the desired limit of The results of Examples 1 to 8 are summarised in Table 1 below.

WO'97/47537 PCT/AU97/00324 EXAMPLE NO. 1 2 3 4 5 6 7 8 Number of Gas 2 3 4 4 4 4 4 4 Channels Gas Channel 4.0 4.0 6.0 2.5 2.5 2.5 2.5 Wall Thickness (mm) Gas Channel 16 16 16 10 10 10 10 Depth (mm) Corrugation 20 20 20 35 35 38 38 38 Depth (mm) Percentage 40% 40% 40% 40% 20% 40% 30% Filler Content Flexural Creep 870 870 870 870 630 870 750 630 Modulus (MPa) Maximum 46.4 41.8 33.1 35.9 49.6 28.3 32.9 39.1 Displacement (mm) Approximate 2760 2910 3490 2700 2700 2700 2700 2700 Volume (cm 3 From the gas channels and a table above, it is evident that four corrugation depth of 38mm provides the best structural stiffness for the design of the bin divider.

The interpolated results for a range of talc contents based on four gas channels and 38 mm corrugation depth (as in Examples 6, 7 and 8) are listed in Table 2 below.

Percentage Filler Content 20% 25% 30% 35% Interpolated Flexural Creep Modulus 630 690 750 810 870 (MPa) Interpolated Maximum Deflection (mm) 39.1 35.7 32.9 30.4 28.3 From Table 2 above it can be seen that all talc contents examined meet the 40mm desired limit of deflection. However, due to the substitution of creep data from suggested equivalent grades of material and the degree of interpolation required to determine Flexural WO 97/47537 PCT/AU97/00324 11 Creep Moduli for the required conditions, it is suggested that a talc content of 20% results in a deflection which too close to the desired limit of 40mm to be considered as passing the performance requirements for the bin divider under the loading conditions described.

It should be appreciated that various other changes and modifications may be made to the embodiment described without departing from the spirit and scope of the invention.

Claims (16)

1. A dividing panel insertable into a bin to divide the bin into independent compartments, the panel having corrugations extending from adjacent an upper edge of the panel to adjacent a lower edge of the panel, and at least one hollow enclosed channel which may be filled with gas, extending from adjacent an upper edge of the panel to adjacent a lower edge of the panel.

2. The panel of claim 1, having at least three corrugations extending across the panel.

3. The panel of claim 1 or claim 2, wherein each corrugation has a depth of between 10 to 50 millimetres.

4. The panel of any one of the preceding claims, wherein the S•thickness of the panel is between 3 to 15 millimetres. .o

5. The panel of any one of the preceding claims, wherein at least two spaced apart parallel said channels are provided across the dividing panel. o 15

6. The panel of any one of the preceding claims, wherein at least some of the channels extend around a mid portion across the dividing panel as this part of the panel is subject to the most deformation.

The panel of any one of the preceding claims, wherein the oe channels are formed integrally with the dividing panel.

8. The panel of any one of the preceding claims, wherein the o channels are formed by injecting gas, such as nitrogen or other gas during formation of the panel to provide an enclosed gas channel.

9. The panel of any one of the preceding claims, wherein the channel wall thickness is between 4 to 6 millimetres. 0@ 25

10. The panel of any one of the preceding claims, wherein the height of the channel is between 10 to 20 millimetres.

11. The panel of any one of the preceding claims, having a peripheral thickened edge.

12. The panel of any one of the preceding claims, wherein the panel is formed from injection-moulded plastic.

13. The panel of any one of the preceding claims, wherein the panel is formed as a single wall structure to minimise the thickness of the panel. 13

14. The panel of any one of the preceding claims, wherein at least some of the channels extend along and in the panel such that the channels are not readily visible from each side of the dividing panel.

The panel of any one of the preceding claims, wherein the channels extend along one or both faces of the panel to form visible longitudinal ribs.

16. A panel substantially as hereinbefore described with reference to the drawings. DATED this 22 nd day of March 1999 OTTO PLASTICS PTY. LTD. 005 786 345) By their Patent Attorneys CULLEN CO. C. C.. C eq.